Gross anatomy of the gastrointestinal system of harp seals ( Phoca groenlandica)

• Published in: Journal of Zoology
• Main Authors: Olsen, M. A., Nilssen, K. T., Mathiesen, S. D.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 1996
• Subjects: North Atlantic; Phoca groenlandica
• Online Access: http://dx.doi.org/10.1111/j.1469-7998.1996.tb05415.x; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.1469-7998.1996.tb05415.x; https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1469-7998.1996.tb05415.x; https://zslpublications.onlinelibrary.wiley.com/doi/pdf/10.1111/j.1469-7998.1996.tb05415.x

The gross anatomy of the gastrointestinal system of 12 harp seals ( Phoca groenlandica ) was investigated. Harp seals have a typical carnivore monogastric stomach. The tissue wet weight of the stomach of harp seals represented 27.01 (S.D. 3.99)% ( n = 12) of the total gastrointestinal tract (GI‐tract). All animals were killed while resting on the ice, and had empty stomachs, but when expanded with water to a 30cm pressure the stomach contained 0.60 to 1.60 litres, representing 1.00 (S.D. 0.26)% ( n = 12) of the body mass. The small intestine ranged in length from 20.44 to 25.32m, being 14.36 (S.D. 1.58) times the body length, and the tissue wet weight constituted 67.61 (S.D. 4.55)% of the total GI‐tract ( n = 12). Both caecum and colon were short, maximally 5 and 78 cm, respectively, being 0.022 (S.D. 0.005) and 0.38 (S.D. 0.06) times the body length ( n = 12). The caecum tissue wet weight was only 0.18 (S.D. 0.04)% of the total GI‐tract weight, while the colon tissue wet weight contributed to 5.33 (S.D. 1.19)% ( n = 12). It is concluded that harp seals have relatively long intestines compared to minke whales eating a comparable diet in the North Atlantic Ocean.